The present invention relates to a transisterized voltage regulator, and more particularly to a regulator having two output terminals for use in, for example, a tuner of the electronic tuning type.
A typical voltage regulator is shown in FIG. 1, where a single transistor 1 of PNP polarity has its collector electrode connected to an input terminal 2 and its emitter electrode connected to an output terminal 3. The base electrode of the transister 1 is connected through a FET (field effect transistor) circuit 4 to the input terminal and also through a zener diode 5 to the ground. The FET has its gate and source electrodes connected to the input terminal 2 and its drain electrode connected to the base electrode of the transistor 1. The FET circuit 4 forms a constant current circuit. Numerals 6, 7 and 8 denote respectively a rectifier diode connected to an AC voltage source (not shown), a smoothing capacitor and a tuner having a power supply input voltage of -B at terminal 9. Numeral 10 denotes a potentiometer for electronic tuning through which a very low current of approximately 2 mA will constantly flow while a large current of approximately 100 mA will flow through the tuner 8.
In such a vlotage regulator, however, the output voltage from the output 3 is applied to both the tuner 8 and potentiometer 10 and thus drift of the output voltage owing to the temperature characteristics of the transistor 1 may affect the tuning voltage of the potentiometer 10.